ObjectiveTo investigate the role of the forkhead/Fox transcription factor 2 (Foxc2) over-expression in regulating osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by Wnt-β-catenin signaling pathways in vitro so as to provide the experimental basis for repairing osteonecrosis of the femoral head. MethodsThe recombinant lentivirus carrying green fluorescent protein (group A) or Foxc2 (group B) were used to transfect the fifth generation rabbit BMSCs, and untransfected BMSCs served as a control (group C). The cell viability was measured with water soluble tetrazolium-1 (WST-1) regent at 72 hours after transfection. After 2 weeks of transfection, the expression of β-catenin in BMSCs was detected by real time fluorescence quantitative PCR, Western blot, and immunofluorescence staining. Meanwhile, the β-catenin inhibitors XAV-939 (0, 0.1, and 1.0 μmol/L) was added in group B; at 2 weeks after osteogenic and adipogenic induction, the gene and protein expressions of collagen type I (COL I), osteocalcin (OCN), and peroxisome proliferator activated receptor gamma 2 (PPARγ-2) were detected by real time PCR and Western blot. ResultsWST-1 results showed that the cell viability of group B (130.85%±0.15%) was significantly higher than that of group A (100.45%±0.35%) (t=7.500, P=0.004) at 72 hours after transfection. At 2 weeks after transfection, the gene and protein expressions of β-catenin in group B were significantly higher than those in group A (P<0.01). After XAV-939 was added in group B, the mRNA and protein expressions of OCN and COL I gradually decreased; the mRNA and protein expressions of PPARγ-2 significantly increased (P<0.05), showing a dose-dependent manner. ConclusionThe over-expression of Foxc2 gene in BMSCs may promote osteogenic differentiation by Wnt-β-catenin signaling pathway.
ObjectiveTo compare the recovery of proprioception of the knee after the anterior cruciate ligament (ACL) reconstruction with remnant preservation or not. MethodsBetween January 2010 and October 2012, 40 patients with ACL rupture were divided into remnant preservation reconstruction group (trial group, n=20) and traditional reconstruction group (control group, n=20). There was no significant difference in gender, age, disease duration, injury causes, preoperative Lysholm scores, and preoperative International Knee Documentation Committee (IKDC) scores between 2 groups (P>0.05). All the patients received ACL single-bundle reconstruction surgery with autologous hamstring tendon transplantation under arthroscope. After operation, the function of knee was assessed by Lysholm and IKDC scores and the proprioception was assessed by joint position sense (JPS) value which was evaluated by passive repeat angle test with isokinetic test system. ResultsAll incisions healed by first intention in 2 groups. The patients were followed up 12-16 months (mean, 14.0 months) in trial group, and 12-15 months (mean, 14.5 months) in control group. At 12 months after operation, the Lysholm and IKDC scores were significantly increased when compared with preoperative scores (P<0.05) in both groups, but no significant difference was found between 2 groups (P>0.05). At 3 months and 12 months after operation in trial group, the JPS values of operated knee at 15, 45, and 75° of flexion were significantly lower than preoperative values (P<0.05), but no significant difference was found between at 3 months and at 12 months after operation (P>0.05). At 3 months after operation in control group, there was no significant difference (P>0.05) in JPS values of operated knee at 15, 45, and 75° of flexion when compared with preoperative ones; but at 12 months after operation in control group, the JPS values of operated knee at 15, 45, and 75° of flexion were significantly lower than those at preoperation and at 3 months after operation (P<0.05). At 3 months after operation, the JPS of operated knee at 15, 45, and 75° of flexion in trial group were significantly lower than those of operated knee in control group (P<0.05), but no significant difference was found between 2 groups at 12 months after operation (P>0.05). At 3 and 12 months after operation in trial group, there was no significant difference (P>0.05) in JPS values at 15, 45, and 75° of flexion between operated and normal knees; at 3 months after operation in control group, the JPS values of operated knee at 15, 45, and 75° of flexion were significantly higher than those of normal knee, but there was no significant difference between operated knee and normal knee at 12 months after operation (P>0.05). ConclusionACL reconstruction with remnant preservation is helpful for recovery of proprioception in knee joint at early stage.